This driver currently supports only SiFive FU540-C000 platform.
The initial version of L2 cache controller driver supports:
- Initial configuration reporting at boot up.
- Support for ECC related functionality.
Signed-off-by: Yash Shah <yash.shah@xxxxxxxxxx>
---
arch/riscv/mm/Makefile | 1 +
arch/riscv/mm/sifive_l2_cache.c | 224 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 225 insertions(+)
create mode 100644 arch/riscv/mm/sifive_l2_cache.c
diff --git a/arch/riscv/mm/Makefile b/arch/riscv/mm/Makefile
index eb22ab4..1523ee5 100644
--- a/arch/riscv/mm/Makefile
+++ b/arch/riscv/mm/Makefile
@@ -3,3 +3,4 @@ obj-y += fault.o
obj-y += extable.o
obj-y += ioremap.o
obj-y += cacheflush.o
+obj-y += sifive_l2_cache.o
diff --git a/arch/riscv/mm/sifive_l2_cache.c b/arch/riscv/mm/sifive_l2_cache.c
new file mode 100644
index 0000000..95f10e4
--- /dev/null
+++ b/arch/riscv/mm/sifive_l2_cache.c
@@ -0,0 +1,224 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * SiFive L2 cache controller Driver
+ *
+ * Copyright (C) 2018-2019 SiFive, Inc.
+ *
+ */
+#include <linux/debugfs.h>
+#include <linux/interrupt.h>
+#include <linux/of_irq.h>
+#include <linux/of_address.h>
+
+#define SIFIVE_L2_DIRECCFIX_LOW 0x100
+#define SIFIVE_L2_DIRECCFIX_HIGH 0x104
+#define SIFIVE_L2_DIRECCFIX_COUNT 0x108
+
+#define SIFIVE_L2_DATECCFIX_LOW 0x140
+#define SIFIVE_L2_DATECCFIX_HIGH 0x144
+#define SIFIVE_L2_DATECCFIX_COUNT 0x148
+
+#define SIFIVE_L2_DATECCFAIL_LOW 0x160
+#define SIFIVE_L2_DATECCFAIL_HIGH 0x164
+#define SIFIVE_L2_DATECCFAIL_COUNT 0x168
+
+#define SIFIVE_L2_CONFIG 0x00
+#define SIFIVE_L2_WAYENABLE 0x08
+#define SIFIVE_L2_ECCINJECTERR 0x40
+
+#define SIFIVE_L2_ERR_TYPE_CE 0
+#define SIFIVE_L2_ERR_TYPE_UE 1
+#define SIFIVE_L2_MAX_ECCINTR 3
+
+static void __iomem *l2_base;
+static int g_irq[SIFIVE_L2_MAX_ECCINTR];
+
+enum {
+ DIR_CORR = 0,
+ DATA_CORR,
+ DATA_UNCORR,
+};
+
+static unsigned int l2_dirfix_addr_high(void)
+{
+ return readl(l2_base + SIFIVE_L2_DIRECCFIX_HIGH);
+}
+
+static unsigned int l2_dirfix_addr_low(void)
+{
+ return readl(l2_base + SIFIVE_L2_DIRECCFIX_LOW);
+}
+
+static unsigned int l2_dirfix_count(void)
+{
+ return readl(l2_base + SIFIVE_L2_DIRECCFIX_COUNT);
+}
+
+static unsigned int l2_datfix_addr_high(void)
+{
+ return readl(l2_base + SIFIVE_L2_DATECCFIX_HIGH);
+}
+
+static unsigned int l2_datfix_addr_low(void)
+{
+ return readl(l2_base + SIFIVE_L2_DATECCFIX_LOW);
+}
+
+static unsigned int l2_datfix_count(void)
+{
+ return readl(l2_base + SIFIVE_L2_DATECCFIX_COUNT);
+}
+
+static unsigned int l2_datfail_addr_high(void)
+{
+ return readl(l2_base + SIFIVE_L2_DATECCFAIL_HIGH);
+}
+
+static unsigned int l2_datfail_addr_low(void)
+{
+ return readl(l2_base + SIFIVE_L2_DATECCFAIL_LOW);
+}
+
+static unsigned int l2_datfail_count(void)
+{
+ return readl(l2_base + SIFIVE_L2_DATECCFAIL_COUNT);
+}
+
+#ifdef CONFIG_DEBUG_FS
+static struct dentry *sifive_test;
+
+static ssize_t l2_write(struct file *file, const char __user *data,
+ size_t count, loff_t *ppos)
+{
+ unsigned int val;
+
+ if (kstrtouint_from_user(data, count, 0, &val))
+ return -EINVAL;
+ if ((val >= 0 && val < 0xFF) || (val >= 0x10000 && val < 0x100FF))
+ writel(val, l2_base + SIFIVE_L2_ECCINJECTERR);
+ else
+ return -EINVAL;
+ return count;
+}
+
+static const struct file_operations l2_fops = {
+ .owner = THIS_MODULE,
+ .open = simple_open,
+ .write = l2_write
+};
+
+static void setup_sifive_debug(void)
+{
+ sifive_test = debugfs_create_dir("sifive_l2_cache", NULL);
+ if (!sifive_test)
+ return;
+
+ if (!debugfs_create_file("sifive_debug_inject_error", 0200,
+ sifive_test, NULL, &l2_fops))
+ debugfs_remove_recursive(sifive_test);
+}
+#endif
+
+static void l2_config_read(void)
+{
+ u32 regval, val;
+
+ regval = readl(l2_base + SIFIVE_L2_CONFIG);
+ val = regval & 0xFF;
+ pr_info("L2CACHE: No. of Banks in the cache: %d\n", val);
+ val = (regval & 0xFF00) >> 8;
+ pr_info("L2CACHE: No. of ways per bank: %d\n", val);
+ val = (regval & 0xFF0000) >> 16;
+ pr_info("L2CACHE: Sets per bank: %llu\n", (uint64_t)1 << val);
+ val = (regval & 0xFF000000) >> 24;
+ pr_info("L2CACHE: Bytes per cache block: %llu\n", (uint64_t)1 << val);
+
+ regval = readl(l2_base + SIFIVE_L2_WAYENABLE);
+ pr_info("L2CACHE: Index of the largest way enabled: %d\n", regval);
+}
+
+static const struct of_device_id sifive_l2_ids[] = {
+ { .compatible = "sifive,fu540-c000-ccache" },
+ { /* end of table */ },
+};
+
+static ATOMIC_NOTIFIER_HEAD(l2_err_chain);
+
+int register_sifive_l2_error_notifier(struct notifier_block *nb)
+{
+ return atomic_notifier_chain_register(&l2_err_chain, nb);
+}
+EXPORT_SYMBOL_GPL(register_sifive_l2_error_notifier);
+
+int unregister_sifive_l2_error_notifier(struct notifier_block *nb)
+{
+ return atomic_notifier_chain_unregister(&l2_err_chain, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_sifive_l2_error_notifier);
+
+static irqreturn_t l2_int_handler(int irq, void *device)
+{
+ unsigned int regval, add_h, add_l;
+
+ if (irq == g_irq[DIR_CORR]) {
+ add_h = l2_dirfix_addr_high();
+ add_l = l2_dirfix_addr_low();
+ pr_err("L2CACHE: DirError @ 0x%08X.%08X\n", add_h, add_l);
+ regval = l2_dirfix_count();
+ atomic_notifier_call_chain(&l2_err_chain, SIFIVE_L2_ERR_TYPE_CE,
+ "DirECCFix");
+ }
+ if (irq == g_irq[DATA_CORR]) {
+ add_h = l2_datfix_addr_high();
+ add_l = l2_datfix_addr_low();
+ pr_err("L2CACHE: DataError @ 0x%08X.%08X\n", add_h, add_l);
+ regval = l2_datfix_count();
+ atomic_notifier_call_chain(&l2_err_chain, SIFIVE_L2_ERR_TYPE_CE,
+ "DatECCFix");
+ }
+ if (irq == g_irq[DATA_UNCORR]) {
+ add_h = l2_datfail_addr_high();
+ add_l = l2_datfail_addr_low();
+ pr_err("L2CACHE: DataFail @ 0x%08X.%08X\n", add_h, add_l);
+ regval = l2_datfail_count();
+ atomic_notifier_call_chain(&l2_err_chain, SIFIVE_L2_ERR_TYPE_UE,
+ "DatECCFail");
+ }
+
+ return IRQ_HANDLED;
+}
+
+int __init sifive_l2_init(void)
+{
+ struct device_node *np;
+ struct resource res;
+ int i, rc;
+
+ np = of_find_matching_node(NULL, sifive_l2_ids);
+ if (!np)
+ return -ENODEV;
+
+ if (of_address_to_resource(np, 0, &res))
+ return -ENODEV;
+
+ l2_base = ioremap(res.start, resource_size(&res));
+ if (!l2_base)
+ return -ENOMEM;
+
+ for (i = 0; i < SIFIVE_L2_MAX_ECCINTR; i++) {
+ g_irq[i] = irq_of_parse_and_map(np, i);
+ rc = request_irq(g_irq[i], l2_int_handler, 0, "l2_ecc", NULL);
+ if (rc) {
+ pr_err("L2CACHE: Could not request IRQ %d\n", g_irq[i]);
+ return rc;
+ }
+ }
+
+ l2_config_read();
+
+#ifdef CONFIG_DEBUG_FS
+ setup_sifive_debug();
+#endif
+ return 0;
+}
+device_initcall(sifive_l2_init);
--
1.9.1
